Sylvia Plath with her parents, Aurelia and Otto. Photograph: Mortimer Rare Book Room, Smith College

Sylvia Plath would never have wanted her semi-autobiographical novel The Bell Jar published under her name while her mother, Aurelia Plath, was still alive, one of the writer's friends has said.

Elizabeth Sigmund, one of Plath's closest confidants, also accused the writer's former husband, Ted Hughes, and his sister, Olwyn Hughes, of deliberately missing the dedication to her from the first edition which was published under Plath's own name, in 1966, "because they didn't want anyone who knew Sylvia to have any contact with the press".

When The Bell Jar was first published in January 1963, it appeared under the pseudonym Victoria Lucas, because, according to Sigmund, the author did not want to upset Aurelia or other people who feature in the book. Aurelia died in 1994.

That first edition contained the dedication "For Elizabeth and David" – referring to Elizabeth Sigmund and her husband, David, the science fiction writer. When the novel was republished under Plath's own name, three years after her suicide, the dedication was not included.

Sigmund said she wrote to the Times Literary Supplement when she realised that her name was missing, expressing her distress. She then received an apology from Charles Moneith, the chairman of Faber and Faber, who said they hadn't noticed there was a dedication. This, suggests Sigmund, was unlikely. "I don't believe they didn't notice it, because it was in an unusual place. It was directly opposite chapter one. You couldn't miss it."

Faber and Faber told the Guardian that it had nothing in its archive "which would support the view that Faber had any knowledge that Plath allegedly did not want the novel to be published under her own name in the event of her death. There's also nothing that would suggest that Elizabeth Sigmund was deliberately left off the dedication for our original hardback edition of the novel."

But Sigmund has now been able to produce further correspondence. After she wrote to the TLS, she received a letter from Olwyn Hughes, whom Ted Hughes had appointed as Plath's executor and literary agent following her death, which states that "Faber were probably trying to save paper."

When Sigmund wrote back to Monteith to ask him about this, he wrote: "That seems to me to be completely meaningless." He added: "I certainly never heard that Sylvia had expressed a wish that The Bell Jar should never be published under her own name. When we published it posthumously under Sylvia's real name, we did so with the express consent of Ted and Olwyn Hughes."

Sigmund said in an interview with the Guardian: "There are two sides to this, of course. Because it was a brilliant book, one is glad that it was credited to her. But also you have to regard her wishes. If she said she didn't want to hurt people's feelings, by having it published under her own name … I certainly think that Ted and Olwyn should have mentioned that. And then Faber would have had to make up their minds. But for Monteith to say that he'd certainly never heard that – it just seems that they were keeping it from Faber."

Carl Rollyson, the author of a new Plath biography, American Isis: The Life And Art of Sylvia Plath, supports the view that Plath would not have wanted the book published in her mother's lifetime. He said: "I think Sylvia certainly was very sensitive to all that."

He said there was "no love lost" between Plath and Olwyn Hughes, a view also held by Sigmund, who claims that "Olwyn hated her".

Olwyn Hughes admitted she thought Plath was "a monster". Yet she also expressed sympathy for the author.

"She was a very agonised lady. She had to battle to live every day – as you might think from The Bell Jar. When I read it after she died, I just wept."

On the matter of using Plath's own name on the book, she denied this was controversial. "What people want after they're dead. That just goes."

She said that by the time the book was first published under Plath's name, "everybody really seemed to know it was by her. Her friends all knew. There seemed no point in not publishing under her own name. Nobody was going to be able to keep the secret about who wrote the book for decades."

Sylvia Plath travelled to New York City in June 1953 full of anticipation about a guest editorship at Mademoiselle magazine. She was to return home a changed person, as this extract from Andrew Wilson's biography reveals